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Not Applicable
Several attempts have been made to provide skin treatments that exfoliate and cleanse the skin without abrasives. Recently, the use of alphahydroxy acids (AHA""s) such as glycolic, lactic, salicylic or fruit acids have been utilized, with only partial success. The use of AHA""s increases skin collagen levels and skin thickness. However, there are side effects common to AHA""s. In particular, AHA""s may cause stinging, redness, irritation and crusting of the skin. Moreover, reports have emerged connecting AHA""s to skin damage including serious skin bums.
Topical formulations comprised of straight, all carbon backbone, dicarboxylic acids have been proposed to replace the fashionable AHA""s. Examples of these dicarboxylic acid formulas are found in U.S. Pat. Nos. 4,292,326; 4,386,104, 5,385,943 and 4,885,282.
The problem with use of these dicarboxylic acids is their inherent insolubility in aqueous solutions. Such all carbon backbone, dicarboxylic acids are solids at ambient temperatures, and are extremely difficult to work with, especially with cosmetic or cleanser carriers, the most common of which is water.
There is therefore a need in the art for a class of compounds that can be used as mild, exfoliating actives for topical treatment of skin.
There is also a need in the art for a mild, exfoliating topical composition which contains a water soluble compound that is amenable for manufacturing aesthetically acceptable cosmetic or dermatologic products.
The present invention uses a novel mixture of ingredients to accomplish many of the benefits of AHA""s, with fewer side effects, and uses a compound that is readily soluble in water. The present invention uses a phosphate salt, and particularly sodium tripolyphosphate in concentrations of between 0.5 and 40% by weight.
Previously, sodium tripolyphosphate in preferable concentrations of about between 78 to 87% has been added to shaving cream for softening water used in shaving, as described in U.S. Pat. No. 4,963,351 issued to Weston on Oct. 16, 1990. However it has been found that this formulation is inappropriate for cleansing and treatment of skin, because the concentration of sodium tripolyphosphate is too great, and may cause undue irritation of the skin.
Another formulation containing sodium tripolyphosphate is disclosed in U.S. Pat. No. 4,923,684 issued to Ibrahim , et al. on May 8, 1990 for Tripolyphosphate-containing anti-calculus toothpaste, the disclosure of which is incorporated herein by reference. This formulation contains fluoride saccharin and flavor, which are all inappropriate for use on human skin.
Finally, it has long been known that sodium tripolyphosphate is useful for treating meat and poultry, to increase shelf life and aid in retaining color.